1. Field of the Invention
The present invention generally relates to an electronic circuit technique, in particular, to an analog-to-digital converter (ADC) having a high precision analog-to-digital conversion function.
2. Description of Related Art
Flat panel displays, such as liquid crystal displays (LCDs), have been extensively adopted in recent years. The LCDs have advantages of low power consumption, physical compactness, light weight, high resolution, high color saturation, long life time, and so forth. Hence, the LCDs have been widely applied to electronic products closely associated with our daily lives, such as laptop or desktop computers and LCD TVs. Here, a driving circuit in the LCD is a crucial element which drives the LCD, affects display quality of the LCD and the manufacturing costs thereof.
Tests are performed before packaging the driving circuit for the LCD, so as to ensure that the LCD is operated as normal. For example, a chip probe (CP) test may be performed for the driving circuit for the LCD, such as a source driving die. Since an analog voltage outputted by the source driving die should be as accurate as it may be, a precise and expensive analog testing machine is required for inspecting the voltages of the output pins in each of the source driving dies when the CP test is performed on the source driving die.
Nevertheless, the number of output pins in each of the source driving dies increases along with an increasing dimension of an LCD panel in the LCD. As a result, workload arisen from the CP test increases. Hence, developing a fast and inexpensive apparatus for testing in replacement of the conventional expensive analog testing machine is imperative at the moment.